package com.avic.rong.richEditor.widget;

import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ScrollView;

/**
 * Creater: Created by wangyz on 2019/9/23.
 * Email: 936804097@qq.com
 */
public class MyScrollView extends ScrollView {
//    private GestureDetector mGestureDetector;
//    View.OnTouchListener mGestureListener;
//
//    public MyScrollView(Context context, AttributeSet attrs) {
//        super(context, attrs);
//        mGestureDetector = new GestureDetector(context, new YScrollDetector());
//        setFadingEdgeLength(0);
//    }
//
//    @Override
//    public boolean onInterceptTouchEvent(MotionEvent ev) {
//        return super.onInterceptTouchEvent(ev) && mGestureDetector.onTouchEvent(ev);
//    }
//
//    // Return false if we're scrolling in the x direction
//    class YScrollDetector extends GestureDetector.SimpleOnGestureListener {
//        @Override
//        public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
//            if (Math.abs(distanceY) > Math.abs(distanceX)) {
//                return true;
//            }
//            return false;
//        }
//    }
    /**
     *
     */
    public ScrollView parentScrollView;

    public MyScrollView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    private int lastScrollDelta = 0;

    public void resume() {
        overScrollBy(0, -lastScrollDelta, 0, getScrollY(), 0, getScrollRange(), 0, 0, true);
        lastScrollDelta = 0;
    }

    int mTop = 10;

    /**
     * 将targetView滚到最顶端
     */
    public void scrollTo(View targetView) {
        int oldScrollY = getScrollY();
        int top = targetView.getTop() - mTop;
        int delatY = top - oldScrollY;
        lastScrollDelta = delatY;
        overScrollBy(0, delatY, 0, getScrollY(), 0, getScrollRange(), 0, 0, true);
    }

    private int getScrollRange() {
        int scrollRange = 0;
        if (getChildCount() > 0) {
            View child = getChildAt(0);
            scrollRange = Math.max(0, child.getHeight() - (getHeight()));
        }
        return scrollRange;
    }

    int currentY;

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        if (parentScrollView == null) {
            return super.onInterceptTouchEvent(ev);
        } else {
            if (ev.getAction() == MotionEvent.ACTION_DOWN) {
// 将父scrollview的滚动事件拦截
                currentY = (int) ev.getY();
                setParentScrollAble(false);
                return super.onInterceptTouchEvent(ev);
            } else if (ev.getAction() == MotionEvent.ACTION_UP) {
// 把滚动事件恢复给父Scrollview
                setParentScrollAble(true);
            } else if (ev.getAction() == MotionEvent.ACTION_MOVE) {
            }
        }
        return super.onInterceptTouchEvent(ev);
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        View child = getChildAt(0);
        if (parentScrollView != null) {
            if (ev.getAction() == MotionEvent.ACTION_MOVE) {
                int height = child.getMeasuredHeight();
                height = height - getMeasuredHeight();
// System.out.println("height=" + height);
                int scrollY = getScrollY();
// System.out.println("scrollY" + scrollY);
                int y = (int) ev.getY();
// 手指向下滑动
                if (currentY < y) {
                    if (scrollY <= 0) {
// 如果向下滑动到头，就把滚动交给父Scrollview
                        setParentScrollAble(true);
                        return false;
                    } else {
                        setParentScrollAble(false);
                    }
                } else if (currentY > y) {
                    if (scrollY >= height) {
// 如果向上滑动到头，就把滚动交给父Scrollview
                        setParentScrollAble(true);
                        return false;
                    } else {
                        setParentScrollAble(false);
                    }
                }
                currentY = y;
            }
        }
        return super.onTouchEvent(ev);
    }

    /**
     * 是否把滚动事件交给父scrollview
     *
     * @param flag
     */
    private void setParentScrollAble(boolean flag) {
        parentScrollView.requestDisallowInterceptTouchEvent(!flag);
    }

}
